(batch manager branch): Fix audio

[QuintinMouser]

Audio was not working with batch manager. There were missing variables, so I copied them from their original locations from other functions.

Obviously this can be refactored later as you like, but for now this does fix audio.

By the way, the batch manager works great, so thanks!

If I see any more issues, I'll try to fix them or let you know.

[AustinMroz]

Thank you very much for catching this and for testing the batching functionality itself.

At present, there's two blocking issues I'm hoping to resolve before merging:

• Migrating the queuing of subsequent batch executions to occur on the server side so that
  • A batch is properly reset if an error occurs in the middle of a batch
  • The workflow can't change mid-batch by the user making changes in the webui
  • There is increased compatibility with the occasional user that doesn't utilize the webui.
• Do some increased testing to ensure the switch from subprocess.run back to subprocess.Popen doesn't break anything (see #76)